Tesco Clubcard (commonly referred to and branded as Clubcard) is the loyalty card of British supermarket chain Tesco. The Clubcard scheme operates in the United Kingdom, Ireland, Czech Republic, Slovakia, Hungary and several other countries. As of 2017, there were over 17 million users in the United Kingdom. History In 1993, Terry Leahy asked the Tesco marketing team to investigate the potential of loyalty cards. In the past Tesco had run Green Shield Stamps as a promotional tool which rewarded people for visits and spend, but gained no customer information. The initial team researched programmes across the world and developed a proposal which showed that a loyalty card could be very effective. The key change since the days of Green Shield Stamps was the ability to track individual customer behaviour cost-effectively using a magnetic stripe card. In 1994, Grant Harrison attended a conference where Clive Humby from marketing firm dunnhumby was speaking. Dunnhumby was already working with clients such as Cable & Wireless and BMW, and Harrison approached them to help with the loyalty card project. Successful trials throughout 1994 led to the Tesco board asking Harrison and Humby to present to the annual Board strategy session. The first response from the board came from Tesco's then-chairman Lord MacLaurin, who said, "What scares me about this is that you know more about my customers after three months than I know after 30 years." Incidents In January 1995, Frank Riolfo, a former lance-corporal of the Royal Army Medical Corps, blackmailed Tesco, forcing the introduction of the previously trialled discount card. After first contaminating food with (what turned out to be fake) HIV-infected blood in a store in Kettering, Riolfo demanded payment via Tesco's new loyalty card system. He specified that the cards were to contain magnetic strips, allowing them to function secretly as ATM cash withdrawal cards. Coded copies of the PIN code were published under his instruction in national newspapers. Clubcard was subsequently launched nationally with a Direct Marketing campaign by Evans Hunt Scott, Terry Hunt's advertising agency. Customers, including Riolfo's wife, signed up to the scheme and collected a card. Riolfo and his wife then toured the country withdrawing a total of £7,500 cash on 73 occasions until they were eventually caught on 22 April 1995. Frank Riolfo pleaded guilty and was jailed for six years, after appeal. The loyalty card scheme was not discontinued, with Tesco already planning